The present disclosure relates to a toner supply device and an image forming apparatus including the toner supply device.
Conventionally, an electrophotographic type image forming apparatus includes a toner supply device capable of supplying toner to an image carrier (e.g., a photosensitive drum). The toner supply device includes, for example, a toner case (e.g., a toner container) which contains the toner, and a mounting member (e.g., an intermediate tank or a developing unit) on which the toner case is detachably mounted.
Among toner supply devices having such a configuration, there is a device having a configuration in which a remaining amount of the toner within the mounting member is detected by a level sensor and toner supply from the toner case to the mounting member is controlled on the basis of a result of the detection. However, when such a configuration is employed, the level sensor and a complicated supply mechanism are required, which causes cost increase.
Meanwhile, among toner supply devices, there is a device having a configuration in which the toner is always continuously supplied from the toner case to the mounting member during a printing operation. When such a configuration is employed, it is made possible to assuredly supply the toner from the toner case to the mounting member without using a level sensor and a complicated supply mechanism.
However, when such a configuration is employed, as long as the toner remains within the toner case, the toner is always present at a connection portion between the toner case and the mounting member. Thus, when it is attempted to mount or detach the toner case onto or from the mounting member in a state where the toner is present at the connection portion, the toner case drags the toner present at the connection portion between the toner case and the mounting member, and thus the surface of the toner case is made dirty.